/*
BEM设计模式
模块(没有前缀，多个单词用 - 连接)
元素(元素在模块之后，可以有多个层级，以 __ 连接)
修饰(某元素、或者某模块特别的状态，必须有一个状态名和状态值，使用 _ 连接)
*/

.header{
    background-color: #f7f7f7 ;
}

.header__wrap{
    margin: 0 auto;
    height: 80px;
    width: 1200px;
    position: relative;
}

.header__logo{
    width: 150px;
    height: 40px;
    line-height: 40px;
    font-size: 20px;
    color: #07111b;
    text-indent: 50px;
    background:url(../img/logo.png) no-repeat;
    background-size: 40px 40px;
    position: absolute;
    top: 50%;
    margin-top: -20px;
    left: 20px;
}

.header__nav{
    position: absolute;
    right: 20px;
    height: 40px;
    top: 50%;
    margin-top: -20px;
}

.header__nav-item{
    font-size: 14px;
    color: #07111b;
    line-height: 40px;
    float: left;
    padding-left: 40px;
    
}

/* .header__nav-item:hover{
    color: #f01400; 
} */

.header__nav-item_status_active{
    color: #f01400; 
    position: relative;
}

/* .header__nav-item_status_active::after{
    content: ' ';
    display: block;
    width: 100%;
    height: 2px;
    position: absolute;
    background-color: #f01400;
} */

.header__nav-item_custom_button{
    background: #000;
    color: #f4f4f5;
    text-align: center;
    width: 90px;
    border-radius: 3px;
    padding: 0;
    margin-left: 40px;
}
 
/* 第一屏 */
.screen-1{
    height: 800px;
    background-color: #efefef;
    background: url(../img/bg-screen-1.png) no-repeat center;
    position: relative;
    background-size: cover;
    
}

.screen-1__heading{
    margin: 0;
    padding: 0;
    font-weight: normal;
    font-size: 46px;
    color: #4d555d;
    text-align: center;
    padding-top: 152px;
}

.screen-1__heading b{
    color: #f01400;
    font-weight: normal;
}

.screen-1__phone{
    width: 1375px;
    height: 305px;
    background: url(../img/screen-1-phone.png) no-repeat center;
    position: absolute;
    left: 50%;
    margin-left: -687px;
    bottom: 180px;
    z-index: 2;
}

.screen-1__shadow{
    width: 1233px;
    height: 411px;
    background: url(../img/screen-1-shadow.png) no-repeat center;
    position: absolute;
    left: 50%;
    margin-left: -616px;
    bottom: 0px;
    z-index: 1;
    opacity: 0.6;
}

/* 第二屏 */
.screen-2{
    background-color: #fafafa;
    height: 800px;
    position: relative;
    overflow: hidden;
}

.screen-2__heading{
    margin: 0;
    padding: 0;
    font-weight: normal;
    font-size: 46px;
    line-height: 46px;
    color: #f01400;
    text-align: center;
    padding-top: 96px;
}

.screen-2__heading__subheading{
    margin: 0;
    padding: 0;
    font-weight: normal;
    font-size: 16px;
    color: #2c3137;
    text-align: center;
    padding-top: 25px;
    line-height: 28px;
}

.screen-2__phone{
    width: 928px;
    height: 873px;
    background: url(../img/screen-2-phone.png) no-repeat center;
    position: absolute;
    left: 50%;
    margin-left: -464px;
    bottom: -345px;
}

.screen-2__point{
    width: 108px;
    padding-right: 112px;
    height: 22 px;
    font-size: 22px;
    color: #4d555d;
    background: url(../img/icon-point-right.png) no-repeat center right;
    position: absolute;
}

.screen-2__point_custom_right{
    padding-left: 112px;
    background: url(../img/icon-point-left.png) no-repeat center left;
}

.screen-2__point_i_1{ 
    top: 150px;
    left: -164px;
}
.screen-2__point_i_2{
    top: 30px;
    right: 10px;

}
.screen-2__point_i_3{
    top: 330px;
    right: -95px;
}

/* 第三屏 */
.screen-3{
    background-color: red;
    height: 800px;
    overflow: hidden;
    background: url(../img/bg-screen-3.png) no-repeat center;
    background-size: cover;
}

.screen-3__wrap{
    margin: 0 auto;
    height: auto;
    width: 1200px;
    position: relative;
}

.screen-3__heading{
    font-weight: normal;
    font-size: 46px;
    line-height: 46px;
    color: #ffffff;
    text-align: left;
    padding-top: 94px;
}

.screen-3__heading__subheading{
    font-weight: normal;
    font-size: 16px;
    color: #ffffff;
    text-align: left;
    padding-top: 25px;
    line-height: 28px;
} 

.screen-3__phone{
    width: 750px;
    height: 873px;
    background: url(../img/screen-3-phone.png) no-repeat center top;
    position: absolute;
    right: 0;
    top: 195px;
}

.screen-3__features{
    position: absolute ;
    top: 395px;
    left: 0;
    width: 320px;
    height: 280px;
}

.screen-3__features__item{
    width: 138px;
    height: 118px;  
    border: 1px solid #cb7173;
    margin: 0 20px 20px 0;
    float: left;
    border-radius: 4px;
    color: #ffffff;
    text-align: center;
}
.screen-3__features__item__number{
    height: 36px;
    font-size: 36px;
    line-height: 36px;
    padding: 28px 0 8px;
}
 
.screen-3__features__item__describe{
    height: 14px;
    font-size: 14px;
    line-height: 14px;
}

/* 第四屏 */
.screen-4 {
    background-color: #ffffff;
    height: 800px;
    position: relative;
    overflow: hidden;
}

.screen-4__wrap{
    margin: 0 auto;
    height: auto;
    width: 1200px;
    position: relative;
}

.screen-4__heading{
    font-weight: normal;
    font-size: 46px;
    line-height: 46px;
    color: #f01400;
    text-align: center;
    padding-top: 135px;
}

.screen-4__heading__subheading{
    font-weight: normal;
    font-size: 16px;
    color: #464a4f;
    text-align: center;
    padding-top: 29px;
    line-height: 28px;
} 

.screen-4__phone{
    width: 750px;
    height: 873px;
    background: url(../img/screen-3-phone.png) no-repeat center top;
    position: absolute;
    right: 0;
    top: 195px;
}

.screen-4__type{
    width: 1260px;
    height: 270px;
    position: absolute;
    top: 304px;
}

.screen-4__type__item{
    width: 220px;
    margin-right: 90px;
    height: 270px;
    float: left;
    position: relative;
    text-align: center;
    background-size: cover;
}

.screen-4__type__item_i_1{
    background: url('../img/phone-1.png') no-repeat left top;
}

.screen-4__type__item_i_2{
    background: url('../img/phone-2.png') no-repeat left top;
}

.screen-4__type__item_i_3{
    background: url('../img/phone-3.png') no-repeat left top;
}

.screen-4__type__item_i_4{
    background: url('../img/phone-4.png') no-repeat left top;
}

.screen-4__type__item__color{
    width: 100%;
    height: 14px;
    line-height: 14px; 
    font-size: 14px;
    color: #2c3238;
    position: absolute;
    bottom: -44px;
}

.screen-4__type__item__storage{
    width: 100%;
    height: 12px;
    line-height: 12px; 
    font-size: 12px;
    color: #a4a9ae;
    position: absolute;
    bottom: -66px;
}

/* 第五屏 */
.screen-5 {
    height: 800px;
    background-color: #d9dde1;
    position: relative;
    overflow: hidden;
}

.screen-5__bg{
    height: 433px;
    width: 1920px;
    background: url(../img/bg-screen-5.png) no-repeat center;
    background-size: contain;
    position: absolute;
    left: 50%;
    margin-left: -960px;
    bottom: -100px;
}

.screen-5__heading{
    font-weight: normal;
    font-size: 46px;
    line-height: 46px;
    color: #f01400;
    text-align: center;
    padding-top: 130px;
}

.screen-5__heading__subheading{
    font-weight: normal;
    font-size: 16px;
    color: #464a4f;
    text-align: center;
    padding-top: 29px;
    line-height: 28px;
} 

/* 第六屏 */
.screen-buy {
    height: 80px;
    padding: 120px 0;
    background: #2b333b url('../img/bg-screen-buy.png') center no-repeat;
    position: relative;
    overflow: hidden;
    text-align: center;
} 

.screen-buy__button{
    height: 80px;
    width: 240px;
    text-align: center;
    line-height: 80px;
    font-size: 24px;
    color: #ffffff;
    background-color: #f01414;
    display: inline-block;
    border-radius: 4px;
    transition: all 0.5s;
}

.screen-buy__button:hover{
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
}

/* 页脚 */
.footer{
    height: 80px;
    line-height: 80px;
    text-align: center;
    color: #ffffff;
    font-size: 12px;
    background-color: #07111b;
}

.outline{
    position: fixed;
    padding: 5px 10px;
    bottom: 120px;
    right: 0;
    z-index: 3;
    background-color: #ffffff;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.5);
}

.outline__item{
    display: block;
    width: 50px;
    height: 30px;
    line-height: 30px;
    text-align: center;
    padding: 5px 0;
    background-color: #ffffff;
    margin-top: 5px;
    border-top: 1px solid #efefef;
    color: #93999f;
}

.outline__item:first-child{
    border: none;
}

.outline__item_status_active{
    color: red;
}

.header__nav-tip{
    position: absolute;
    width: 30px;
    height: 2px;
    background-color: red;
    bottom: -2px;
    left: 0;
    margin-left: 40px;
    transition: all 0.5s;
}